Recording systems



March 5, 1957 D. MITCHELL ErAL RECORDING SYSTEMS 3 Sheets-Sheet 1 FiledMarch 3. 1954 om W FW n.. MW no y. Mm DsEw/.M R B m w w 10m NG. .QQ w

ATTORNEY March 5, 1957 D. MITCHELL ETAL RECORDING SYSTEMS 3 Sheets-Sheet2 Filed March 3, 1954 D. MITCHELL ETAL RECORDING SYSTEMS March 5, 1957Filed March 3, 1954 D. M/TCHE/ L By E. VROOM ATTORNEY /lVl/ENTORS UnitedStates Patent O RECORDING SYSTEMS Doren Mitchell, Martinsville, N. I.,and Edward Vroom,

Brooklyn, Conn., assignors to Bell Telephone Laboratories, Incorporated,New York, N. Y., a corporation of New York Application March 3, 1954,Serial No. 413,785 13 Claims. (Cl. 34644) This invention relates tomagnetic recording systems and more particularly to systems for sortingand assembling magnetically recorded information. i

Magnetic recorders are a convenient means of recording information sincea large amount of information may berecorded on a small amount ofmagnetic medium. Characters such as letters or numbers may be recorded'as magnetized spots wherein the position, or magnetic characteristic ofeach spot, indicates the particular character represented by it.

Magnetic recorders are utilized in automatic telephone systems forstoring call -or message information. By transforming the messageinformation into electrical pulses and applying these pulses to a highspeed magnetic medium, the information is made accessible for reading orreproduction, as, for example, in automatic message accounting systemsof the type disclosed in Patent 2,594,495 granted April 29, 1952 to I.B. Retallack. The present invention pertains to a magnetic System forautomatically assembling related items of information recorded in randomsequence on la magnetic medium. For example, the information recorded onthe magnetic medium could be provided at a telephone central oflce inthe form of a plurality of entries for each call which are separated bymany other entries for other calls. It is necessary to sort out theinitial, the ianswer and the disconnect entries for a particular call inorder to properly bill the subscriber for the call. The magnetic readingand sorting system for the central ol'lice magnetic medium must be ableto recognize, translate and direct the recorded entry signals to propersorting units.

In one specific embodiment o f the present invention, the information tobe sorted is in the form of sets of digits on a primary magnetic tape.The digits are coded on a twoout-of-five pulse-time modulation basis onthe primary tape. electrical indication of the recording to anelectronic counting circuit and to a magnetic delay device. The countingcircuit and delay device are preset by switches to function, or sort, inaccordance with any digit of the entry on the primary tape, to operateone of ten recording tapes. The sorting digit determines which one ofthe ten recording tapes is to be utilized in recording the informationstored in the delay device. Each of the ten recording tapes can besorted, in a similar manner, with respect to a 4different digit of theentry to provide Vfor ,a total of one hundred sorted recording `tapesfrom the original primary tape. The primary tape, therefore, can besorted with respect to any number of digits to provide for any factor often sorted outputs,

It is an object of the present invention to provide for a magneticsorting system presenting information on a plural-ity of magnetickoutput tapes in laccordance with any recorded digit of a lplurality ofinformation entries -upon a magnetic input tape.

Another object of the invention `is the provision, of a A magneticreading head provides an 2 sorting system, having a plurality of outputtapes and a magnetic delay circuit which allows for the selection of oneof the tapes and which allows also for start-stop operation of theselected tape.

Still another object of the invention is the provision of a magneticsorting system wherein a plurality of entries on a magnetic medium aresorted in accordance with predetermined elements of each entry. l

A further object of the invention is to provide delay' means in asorting system which stores the information to be sorted until after theselection and acceleration to recording speed of a magnetic output tape.

Still another object of the invention is the provision in a recordingsystem of a magnetic digit analyzer for determining the number of#digits in each entry to be sorted and for stopping the operation of aselected recording device after the recording of the last digit of saidentry.

Still another object of the invention is to provide a sorting systemhaving a digit analyzer for determining the character of the sortingdigit, which may be any digit of a multidigital entry, and for selectingone of a plurality of recording devices in accordance therewith.

Further objects and advantages will become apparent to those skilled inthe art upon consideration of the following description taken inconjunction with the drawings wherein:

Figs. 1, 2 and 3 when arranged in accordance with Fig. 4 illustrate themagnetic sorting system of the present invention; and

Fig. 4 illustrates the arrangement of Figs. l, 2 and v3.

The first digit of thel reference numbers of the various componentsshown in Figs. l through 3 indicates the gure in which the componentappears. For ex ample, component 102 is shown in Fig. 1.

The input information to be sorted is provided on a primary magnetictape 1.01 which passes over the guide wheels 102. ln the specificembodiment of the present invention illustrated, the information onprimary tape 101 is digital information coded on a pulse-time modulationbasis. The principles of the present invention are not necessarilyrestricted to the processing of digital information but any informationcoded on a pulse-time modulation basis may 'ne processed. The pulse-timemodulation utilized herein is on a twoout-ofve basis for each digit. 1nother words, two pulses variably spaced in time are utilized to indicatethe digit. The digits are grouped in entries, each of which may includeup to fty digits in five digit increments. The rst digit of each entryindicates the number of digits in the entry with a 0 indicating livedigits, a 1 indicating ten digits, a 2 indicating fifteen digits, etc.The sorting of the entries as is hereinafter described is accomplishedin accordance with anyY digit of the entry. lf, for example, the sortingis to be in accordance with the lnumber of digits in an entry, thesorting digit would be the first digit of each entry.

To determine the sorting digit, the switches 146, 147 and 310, which arecoupled together, and the switches 139, and 309, which also are coupledtogether, yare utilized. The arithmetic sum of the switch settings ofthe two sets of switches determines the sorting digit. The switchsettings of switches 139, 140 and 310 are in increments of ve and thesettings of switches 146, r147 and 309 are in unit increments. As shownin Figs. i and 3 the switches 146, 147 and 310 are set at terminal 2 andthe switches 139, 140 and 309 are set at terminal 0 indicating thesorting digit to be y2. The entries on tape 101 are accordingly to besorted in ac cordance with the second digit of each entry.

After the switches 146, 1417, 310, 139, 140 and 309 V305, 21) through234, 231i through 234, 12S through 133 and 171) through 18d. The sourceis connected through resistor 304 to the anode of tube 39S and throughthe leads 313, 201 and 262 to the anodes of the tubes 219 through 234,123 through 133, 23) through 234 and 179 through 180. The tubes 12Sthrough 133 form la digit counter 195 for counting the digits in thegroups of digits of an entry. The digit counter 195 is connected to theltubes 170 through 186 which form a group counter 196 yas is hereinafterdescribed. The digit counter 195 can countto tive and the group counter196 can count to ten,

in increments of five so that the combination of counters 195 Yand 196can count to fifty.

vIn addition to supplying anode potential, switch 301 also connectspositive potential to the starting anodes of start tubes 128 and 170 inthe counters 195 and 196, respectively. The source 392 is connectedthrough the operated lower contact of switch 391, the normal contact ofrelay 303, lead 313, lead 201, through the inductor 119 to the anodes oftubes 123 through 133 and through the filter network comprising theresistors 122 and 123 and the capacitor 121, the positively poledvaristor 124 and the resistor 130A, which is center tapped to groundthrough the capacitor 127, to the starting anode of tube 128. Thecathode of the starting tube 128 and the cathodes of tubes 129 through133, as well, are connected to the negative battery 126 through theparallel circuits comprising the capacitors 137 and the resistors 13S.The application of a positive pulse through the capacitor 121, upon theoperation of the starting switch 301, causes tube 128 to ionize. Thepositive potential provided through the inductor 119 is insuicient tocause the ionization of any of the tubes 129 through 133. When tube 128ionizes however between the starting anode and the cathode, thepotential provided through inductor 1.19 is sufficient to sustain theionization which transfers to the main anode. When tube 12S ionizes thepotential upon the starting anode of tube 129 increases due to itsconnection through resistors 135 and 136 tothe contact of resistor 138.The increase in potential at the starting anode of tube 129 isinsufficient to initiate ionization in tube 129 but functions to primeor ready the tube 129 for ionization as is hereinafter described.

In -a similar manner the potential applied from source 302 through lead292 causes the ionization of the starting tube 170 in counter 196 whichis connected to lead 262 through the resistor 166, which is centertapped to ground through capacitor 167, the varistor 168 and the filtercomprising the resistors 181 and 132 and the capacitor 169. The lead 202is also connected through the inductor 12@ to the main anodes of tribes179 through 191% `so that the ionization initiated in tube 179 transfersto its main anode. The cathodes of tubes 176 through 1313 are connectedto the negative potential source 18S through the parallel cir- ,cuitscomprising the capacitors 137 and the resistors 186.

Resistors 186 connected to the cathodes of tubes 17@ through 179 arecenter tapped through resistors 185 and 184 to the next adjacent tubes171 through 189, so that 'tube 171 is primed or readied in a similarmanner as described above in reference to tube 129.

When the first pulse, due to the passage of the first magnetic spot ofthe first digit on tape 191, is induced in the pick-up head or device193, it causes the operation of a multivibrator circuit 100 comprisingthe tubes 165 `and 106. The pulse induced in the head 193, is coupledthrough the coupling capacitor 194 to the grid of the triode tube 1115,and through the parallel circuit consisting of the resistor 114 and thecapacitor 113, to the anode of the triode 196. The cathodes of tubes 10Sand 196 are connected to ground, 4and the anodes 4are connectedrespectively Ithrough the resistors 119 and 115 to the positivepotential sources 111 and 115. The anode of tube 195 is also coupledthrough the capacitor 1417 and resistor 1119 to the cathode of tube1416. The junction lbetween capacitor 197 and resistor 109 is connectedto the grid tube The multivibrator circuit 19t) is biased `by thenegative potential source 112 which is connected to the grid of tube 165through the resistor 108 so that tube is normally non-conducting andtube 196 is normally conducting. The application of a positive pulsethrough capacitor 194, dueto the passage of a magnetic spot on the tape191 adjacent the head 193, triggers multivibrator 199 or reverses theconductive conditions of tubes 195 and 196. As the positive pulse isapplied to the grid of tube 195, conduction therethrough commences andthe potential lat its anode decreases, providing a negative pulsethrough capacitor 1117 to the grid of tube 1116. As the conductionthrough tube 106 decreases the potential at its anode increasesproviding a positive pulse through capacitor 114ito the grid of tube 19Sto further increase the conduction through tube 105.

A pulse is also provided yfrom the anode of tube 106 through thecoupling capacitor 117, which is connected to ground through thenegatively poled -varistor 118, and through the capacitors 134 andresistors 135 to the starting anodes of tubes 129 through 133 describedabove. The varistor 11S prevents the application of negative pulses tothe starting anodes of tubes 129 through 133 when the tube 106 returnsto its original conductive condition. The positive pulse providedthrough the capacitors 134 to the starting anodes of tubes 129 through133, is, in itself, insufficient to initiate ionization Itherein. Thestarting anodes of the tubes 129 through 133, however, are connectedrespectively through the resistors 135 and resistors 136 to themid-connection of the resistors 138 which are each in turn connected tothe next adiacent or preceding cathode of tubes 123 through 132. Sinceas described above tube 129 is primed due to the ionization of tube 123at this time, it ionizes upon the application of the pulse frommultivibrator 19t?. For one of the tubes 129 through 133 to ionizetherefor the preceding tube rnust be ionized and a pulse must beprovided from multivibrator 10i?. The pulse from multivibrator 19%- inaddition to causing the ionization of the primed tube 129 extinguishesthe ionized tube 123 by increasing its cathode potential. The pulse iscoupled through capacitor 117, capacitor 134i, resistor 136, andresistor 133 to the cathode of tube 123. ln this manner a pulse `frommultivibrator 11H1 ionizes the primed tube in counter 195 andextinguishes the ionized tube.

The multivibrator circuit 100 restores to its normal condition inapproximately 4 milliseconds after being triggered. The 4millisecondinterval is sut`cient to bridge all the elements or pulses comprising adigit which is provided in 3.5 milliseconds. 1n other words, themulti-vibrator circuit 100 provides one pulse through the capacitor 117into the counting circuit comprising tubes 128 through 133 for eachdigit.

The ionization across the starting gap of tube 129 transfers across themain gap due to the positive potential provided to the main anodethrough lead 201 and inductor 119, as described above. When tube 129ionizes it primes tube for ionization and causes the ionization of tube171 in counter 196. The cathode of tube 129 is connected respectively tothe starting anodes of the tubes 171 through 180 through the capacitors183 and resistors 184. The increase of potential upon the cathode oftube 129 when it ionizes functions to ionize tube 171 in a similarmanner as the pulse provided by the multivibrator circuit 100 to thestarting arenoso anode of tube 129. The digit k counter 195 is connected:to the group counter 196 only by the connection described above fromthe cathode of tube 129. Whenever tube 129 ionizes a pulse is, providedto the group counter 196 causing it. to step. Since the digit counter195 counts up to tive, a pulse is provided to the group counter 196 onevery fifth pulse so that each step therein is a five-digit or groupstep..

When tube 171 ionizes it provides a positive pulse from its, cathodethrough lead 190v to the spot recording head' 235 which is positionedadjacent the continuons magnetic tape 293, briey mentioned above, of thedigit analyzer 298. The digit analyzer 298 determines the number ofgroups of digits in the entry being sorted as indicated by the iirstdigit'. Only the cathode of tube 171, which ionizes upon the occurrenceoi the first digit, is. connected to the digit analyzer 298. Therotation of tape' 2113 in digit analyzer 298, on the wheels and 2.0',was initiated upon the operation oi' the switch 361 alsoas describedabove. The application of the positive potential to the head 235 inducesa magnetic spot on the tape 2113'. The tape 203 rotates at a uniformrate in. the direction indicated by the. arrow so that the induced'lspot passes adjacent the reading heads 240 through. 24.4.' which arepositioned adjacent the tape 203. As the magnetic spotV passes adjacenteach of the heads 246. through 244 it initiates a pulse therein which iscoupled,v through a capacitor 238, respectively, to the starting.cathode of one of the tubes 230 through 234. The magnetic spot isthereafter erased when it passes adjacent the erase head 236 which isenergized by the alternating-current source 237. At the same time thatthe magnetic spot provided bythe head 23S passes adjacentV the heads241) through 244, the succeeding pulses from the original record tape101 are applied through lead 191 from the pick-upk head 103 to thestarting anode off' tubes 230 through 234. When the pulses provided fromthe heads 24d through 24J- are coincident with the pulsesprovidedthrough lead 191, the tubes 23d through 2.34; to which thesecoincident pulses are applied ionize. v Four pulses are provided foreach digit, a start pulse, two-out-offve digit pulses and an end pulse.rEhe speed o f tape 1111 is at approximately twenty inches per second toprovide for two hundred digits per second. or 5 milliseconds perdigit.Each spot utilizes. .5 'niilliseconi with thje twoout-ofve digit spotsutilizing 2.5 milliseconds andwith the spacing, between digits utilizing1.5 milliseconds. The irst pulse provided by the head 193 is inducedrbythe start pulse of the first digit and provides as described above forthe energization ot the head 235. The Vnext pulses provided by the head163 are the induced digitrpulses, which are. the coincident pulses fortubes 2.3i) through 234. The speed of tape 203 provides for a.5','millisecond interval before the induced magnetic spot reaches head2420 and for a .5 millisecond interval be- Y tween each pair of heads240 through 24d. The two, time modulation, pulses,- through lead 191,coincide with the passage ofthe magnetic spot on tape 203 adjacent twoofthe heads 240through 244 toionize two outof live of the tubes 230through 234. The ionization in the two-out-.of-ve tubes 230 through 24transfers across the mainy gap since the'anodes are connected asdescribed above to source 302 and.. the cathodes are connctedespectivelytothe negative potential source 239 through.the-resistors.246 .shuntedrespectively by capacitors 245.

The.- two of the tubes 230 through 234 which ionized translate;l intoandionize, as is. hereinafter described, cnet-ofthe-.terrtranslator-tubes 211) through 219 to indicatewtheftotalfnumber of digitgroups in the entry. Each vof: the cathodesof tubes236 through 234 isconneetedfto -founout of ten `tubes 210fthrough' 219 through resistors264:l Since thereareve'tub'esZS through 234'fiwithifo'ur connections`fr'om'the"cathode of each tube above in the digit analyzer 298.

23o through 234 and fen or the tubes 210v through 219, each of the tubes210 through 219` is connected to two of the Cathodes of tubes 230through 234. In order for one of the tubes 210 through 219 to ionize, itis necessary for both of the tubes 230 through 234 that arev connectedthereto to be ionized. The two resistors26'4 which are connected to thestarting anode of one of the tubes 210 through 219 form a voltagedivider between two o'f the' cathodes of tubes 230 through 234. If onlyone of these two tubes is ionized the increase of potential at thestarting anode of the associated one" of tubes 210 through 219 isinsuiiicient to cause ionization. When, however, both of the tubes 230through 234 are ionized the increase of potential at the center of thevoltage divider formed by the two resistors 264 is suicient to causeionization. For example, when tubes230 and 233 are ionized, thepotential at the starting anode" of tube 214 increases and tube' 214ionizes. The starting anode of tube 214 is the only starting anode oftubes 210 through 219 which is jointly connected to the cathodes oftubes 230 and 233. The cathodes oftubes 210 through 219 are connectedrespectively through the windings of relays 250 through 259 to thenegative potential sources 263. The ionization of one of the tubes 2115through 219 causes the operation of the associated one of relays 250through 259. For example, when the tube 214 ionizes it causes theoperation of the relay 254 which is associated therewith.

The operation of one of the relays 250 through- 259 provides anindication of the total number of digitsl in the entry since the digitbeing analyzed is the first digit as described above. The tape 203 andtubes 230 through 234v form in this manner the iirst digit analyzer 298and the tubes- 210 through 219 and relays 259 through 259 form atranslator for` the digit analyzer 298. The operation of one of therelays 250 through 259 indicates` the number of groups of five digits inthe entry so that as hereinafter described when the indicated group ofve digits is read by the reading head 103, described above, a timingsequence of events is initiated to terminate the sequence of operationsof the hereinafter describedimag.- netic recordingapparatus 36d. Asdescribed above, only the rst digit initiates a sequence ofoperations'described It is only the cathode of tube 171', which is the 0tube or the tube indicating the rst group.` of ve digits, that isconnectedv to the recording head 235 of the digit analyzer 298; If,vforexample, the entry comprises five groups of five digits each, relay254'would be operated; Six groups, relayv 255 would be operated, etc.

When the second digit pulsesare-induced in the pickup head 103theoperation of the multivibrator 100 causes the ionization of tube andextinguishes tube 129; in ay similar manner as-described above inreference-to the ionization of tube129 and the` extinguishment of tube128. The cathode of tube 130 is connected through contact 2 of'switch147 and capacitor 165, shunted'to ground by the grid-leak resistor V164,to the grid of Ithe control tube 162. The setting of `switches 147, 146,139,' 140, 309 and 310 as described above compensates -for the positionof thesorting digit which, in the illustrative example described herein,`is the second digit. The anode of tube 162 is connected through the 0contact of-switch d to the cathode of tube 171 which is vionized-a'tthistime as described above. Due to the ionization oitube 171 a positivepotential exists at the anode of tube-162 so that the application of apositive potential-.tothe grid thereof causes conduction. In this mannerwhen tubes 130 Vand 171 are ionized,A a positive Vpulse is applied tothegrid-of tube 162. The determinationhofewhen apositive pulse is to beapplied to the gridvof-tube 162 is provided by the: switch 147. Thesettingvof switch 140L`determines during which. group of-vefdigitsav-posi tive potentialwillfbe.provided tothe anode of -tube 162,'.and"the^`sett'ng of switch 147 determines which digit in;

a group of tive digits will cause the application of a positive pulse tothe grid of tube 162.

The cathode of tube 162 is connected to ground through the cathoderesistor 163 and through lead 193 to the recording head 269 of the pulsetimer circuit or digit analyzer 299 which includes the magnetic tape 278briey mentioned above. The tape 278 is supported on the wheels 291 andwas rotated upon the operation of switch 301 as described above. Thetape 278 rotates in a direction indicated by the arrow so that themagnetic spot applied thereto responsive to the conduction of tnbe 162,passes adjacent the :tive reading heads 270 through 274 which haveassociated therewith tubes 281i through 284, respectively. The magneticspot provided by the head 269 is erased as it passes adjacent theerasing head 275 energized by the source 276. The reading heads 271Bthrough 274 are connected respectively through the capacitors 279 to thestarting cathodes of tubes 288 through 284. The starting anodes of tubes284) through 284 are connected to lead 191 described above so that thedigit pulses from the reading head 103 are applied thereto. Thecoincidence of the pulses through lead 191 and from the heads 274 causestwo out of the tive tubes 28S) through 284 to ionize. The pulse timercircuit or digit analyzer 299 operates in a similar manner as the digitanalyzer 298, described above. The main anodes of tubes 28%) through 284are connected to lead 202 as described above, and the cathodes areconnected respectively through the parallel circuits comprising thecapacitors 266 and resistors 267 to the negative potential source 268,Vand in combinations to the starting anodes of the translator tubes 22dthrough 229. The cathodes of tubes 280 through 284 are connected throughthe resistors 265 in a similar manner as described above in reference tothe resistors 264 which connect the tubes 238 through 234 with the tubes210 through 219.

Each of the cathodes of tubes 229 through 229 is connected to a tinalrecording apparatus 360. Only the recording apparatus 360 connected tothe cathode of tube 229 is shown, but a similar recording apparatus 360is connected to each of the cathodes 221) through 228. If the sortingdigit, which in the illustrative example described herein is the seconddigit, is a 9, tube 229 is ionized closing an operating path for relay352 and the magnetic clutch magnet 351) which is connected to thenegative potential source 351. The energization of magnet 350 causes thenal recording tape 353 to come up to recording speed in approximately lmilliseconds as is hereinafter described. When relay 35i) is energized,

it attracts the armature 338 which is resiliently supported by thespring 339. The rotation of armature 33S engages the clutch 341 so thatthe drive or motor unit 342 is coupled to the driving wheel 343 to startthe movement of the recording tape 353. The tape 353 has one turn aboutthe wheel 343 which moves it to the right.

As the tape 353 is moved to the right by wheel 343, the idler 371 isrotated about the pivot 372 on the arm 373 against the tension of thespring 374. As the slack portion of tape 353 about idler 371 is pulledup, it passes between the guide rollers 393 and 394 adjacent an erasecoil 395, record coil 354, an idler 391), to the take-up coil 383. Uponmovement of idler 371, contact 375' is closed and ground is applied torelay 376 which is also connected to the battery 377. The energizationof relay 376 causes the clockwise rotation of armature 379 against thespring 378 to engage the clutch 381. When clutch 381 is engaged, thedrive mechanism 388 rotates a storage reel 382 in a clockwise manner.The take-up coil or reel 383 is rotated in a similar manner by the 387to battery 388. The energization of relay 387 activates the armature 386against the spring 389 to engage the clutch 384. The idler mechanismscomprising idlers 371 and 398 are light so that the amount of mass to beaccelerated by the tape drive 342 is comparatively small. Either or bothof the coils or reels 382 and 383 may have considerable inertia due tothe tape 353 wound therein and clutches 381 and 384 may slip as tape 353is accelerated. The idlers 371 and 390, however, are so positioned andthe slack in tape 353 adequate so that the drive 31552 need not rotatethe reel 383. The delay of time required from closure of the operatingpath of the clutch magnet 350 to the movement of the tape 353 atrecording speed is approximately milliseconds. The tape 353 is cleanedor erased before the recording thereon by the erase magnet 395 which isconnected to the erasing source 396.

Fhe operation of relay 352 described above upon the selection of arecording apparatus 360 connects the recording head d through lead 355to the signal ampli tier 149. The signal or pulse amplifier 149 ampliessignals provided thereto through the 0 terminal of switch 139 frommagnetic delay apparatus 197. The connection to amplifier 149 is fromthe 0 pick-up head 150 which is associated with the magnetic tape 189briely mentioned above. The delay apparatus 197 has ten pick-up headsthrough 159 positioned adjacent the magnetic tape 189 which is supportedon the wheels 148. There are also tive recording heads 141 through 145and an erasing head positioned adjacent the tape 139. The tape 189provides for a delay as is hereinafter described for the signals fromtape 101 for an interval of time equivalent to the time for bringing upthe speed, the tape 353 described above, plus the amount of timecorresponding from the start of the entry to the occurrence of thesorting digit. The pulses induced iu the recording head 103 areconnected through lead 194 and terminal 2 or" switch M6 to the recordinghead 142. The tape 189 is'rotated in a direction indicated by the arrowsso that the setting of switch 146 determines which. one of the tiverecording heads 141 through 145 and correspondingly the length of timeto be selected or utilized between the recording of the pulses of tape189 and the reading thereof by one o the reading heads 158 through 159.The setting of switch 139 determines which one of the ten reading heads151 through 159 will function to provide the re-recorded pulses fromtape 139 to the signal amplifier 149 and thence to one of the ten iinalrecording heads 354. The setting of the two switches 139 and 146therefore determines the delay interval. The recording heads 141 through145 are spaced to provide a S-millisecond difference in delay betweentwo adjacent heads with the head 141 providing for the minimum delay.The heads 150 through 159 are spaced to provide ZS-millisecond delayintervals. The spacings shown on the drawings are only approximate andare not to be taken as indicating the actual times involved. The delayedinformation from the tape 189 is transmitted through lead 355 toWhichever of the final tapes 353 is connected thereto by the operatedone of the ten relays 352.

The recording sequence for an entry proceeds in this manner with thepulses supplied by the reading head 103 being delayed by the delayapparatus 197 until the particular one of tubes 178 through 180, whichis connected to the contact of the operated one of relays 250 through259, is ionized. For example, if relay 254 was operated upon theselection thereof by the digit analyzer 298, the ionization ot' tube 176provides a positive pulse from its cathode through the operated contactof relay 254 and capacitor 261i to the control grid of triode 247. Thetube 247 is normally biased to cut-oft by the con nection of its gridthrough resistor 261 to the negative potential source 262. The anode oftube 247 is con nected to the positive potential source 249 and thecathf ode thereof is connected to ground through the cathode resistor248 and through lead 292 and terminal 2r of switch 310 to the recordinghead 315 of the delay apparatus 340. Tube 247 in this manner repeats thepulse applied thereto to energize one of tive recording heads 314through 318 as selected by the switch 310. In the illustrative exampledescribed herein the switch 310 is set at its terminal 2 so that therecording head 315 is energized. The delay apparatus 340 is similar tothe delay apparatus 197 described above. The recording heads 314 through318 are positioned adjacent the cutot delay tape 311 which is supportedon the wheels 312. Also positioned adjacent the tape 311 are the tenpick-up heads 320 through 329 and the erasing head 330 which isenergized by the source 331. The pick-up heads 320 through 329 areconnected respectively to the ten terminals of switch 309. In thismanner the setting of switches 309 and 310 determines the delay intervalbetween the recording of a magnetic spot on tape 311 and the readingthereof by one of the reading heads 320 through 329. The delay intervalis the same as provided by tape 189 since the switches 310 and 146 areset at the same terminal and the switches 309 and 139 are set at thesame terminal.

As the magnetic spot on tape 311 passes adjacent the selected one ofheads 320 through 329, which in the illustrative example is head 320, apulse is provided through the signal amplifier 306 to the starting anode'of the stop tube 305. The main anode of tube 305 as described above isconnected through the resistor 304, the normal contact of relay 303, thelower operated contact of switch 301 to the positive potential source302. The cathode of tube 305 is connected through the winding of relay303 to the negative potential source 300 and through the capacitor 307to the negative potential source 308. The application of a positivepulse to the starting anode of tube 305 causes the ionization thereofand the operation of relay 303. The operation of relay 303 opens thepath from the positive potential source 302 to lead 313 to remove anodepotential from tubes 128 through 133, 170 through 180, 210 through 234,and 280 through 284. The release of relay 303 is delayed by the etiectof the capacitor 307 which is shunted thereacross. The removal of thepositive potential from lead 313 restores all the tubes to normal andcauses the release of relay 352 and the magnetic clutch magnet 350 ofthe operated one of the final recorders 360. The release of the clutchmagnet 350 allows the clutch 341 to disengage. When the clutch 341 isdisengaged, the continued operation of drive 385 through the engagedclutch 384 raises the idler 390. The raising of idler 390 opens contact392 which opens the energizing path for the clutch magnet 387. Thedeenergization of magnet 387 disengages the clutch 384. In a similarmanner the continued rotation of wheel 382 by drive 380 allows the idler371 to lower and open the contacts 375, the opening of contacts 375opens the operating path of magnet 376 to release the clutch 381. Thetape 315 in this manner slows down and stops upon the deenergization ofthe magnet 350. The tape 350 reaches a standstill in approximately l5milliseconds.

When the original record tape 101 has been run through, ten new tapes353 are provided, sorted in accordance with the second digit of eachentry. The ten tapes 353 may be rewound so that they may be sorted foranother digit, for example, the third digit of each entry. The processof sorting for this additional digit is the same as described aboveexcept that switches 139, 140, 309, 146, 147 and 310 would be reset toindicate the new sorting digit.

in the sorting system described above, the sorting digit may be anydigit in a series of fty digits but such a system is not necessarilyrestricted to the specific embodiment described herein. The sortingsystem, for example, may be used in conjunction with one hundred digitentries and 10 cach group of digits may include eight or ten digitsstead ot tive. The sorting system of the present invention lcan bereadily utilized to sort simultaneously in accordance with a pluralityof sorting digits. The digit analyzer 299 would function for eachsorting digit, and would select one of many recorders 360 upon theoccurrence ot the last sorting digit. Moreover the input may bc provideddirectly as time-modulated pulses instead of from a tape. For example,the magnetic recording system described in our copending applicationSerial No. 413,784 tiled on even date herewith could provide the outputpulses directly to leads 191 and 194 of the present invention and avoidthe intermediate operations of recording on, and reading from a tapesuch as 101 in the present invention.

it is therefore to be understood that the above-described arrangementsare merely illustrative of the application of the principles of thisinvention. Numerous other arrangements may be devised by those skilledin the art without departing from the spirit and scope of the invention.

What is claimed is:

l. A system for sorting a plurality of multidigital entries comprisingselector means; a magnetic medium having recorded thereon groups ofsignals representing said plurality of multidigital entries; readingmeans for converting said groups of signals to time-modulated elecricalpulses; a digit counting circuit controlled by said reading means; amagnetic delay circuit connected to said reading means and controlled bysaid selector means; a plurality of magnetic recording means selectivelyconnectable to said delay circuit; and a digit analyzer controlled bysaid selector means and said counting circuit for connecting one of saidplurality of magnetic recording means to said magnetic delay circuit.

Z. A system for sorting a plurality of multidigital enf tries inaccordance with claim l wherein said digit ana lyzer comprises acontinuous magnetic medium, a recording device positioned adjacent saidmagnetic medium and controlled by said selector means and said countingcircuit, a plurality of reading devices positioned adjacent saidrecording medium, and a coinciden't circuit controlicd by said readingdevices and said reading means for selectively connecting said magneticrecording means to said delay device.

3. A system for sorting a plurality of multidigital entries inaccordance with claim l comprising in addition a second digit analyzercontrolled by said counting circuit upon the occurrence of apredetermined digit which indicates the number of digits in the entry; asecond magnetic delay device controlled by said second digit analyzer;and terminating means controlled by said second delay device fornormalizing said system.

4. A recording system comprising input means for supplying entrieshaving groups of coded signalson a time-modulated basis; a digitselector' for selecting predetermined ones of said groups of codedsignals; a digit analyzer controlled by said digit selector for decodingsaid predetermined ones of said groups of coded signals in each entry; aplurality of recording devices; means controlled by said digit analyzerin accordance with said predetermined groups for selectively operatingsaid recording devices; and delay means connecting said recordingdevices with said input means and controlled by said digit selector fordelaying said coded signals for an interval greater than the time forsupplying said groups preceding said predetermined groups plus the timefor readying said selected recording device.

5. A recording system in accordance with claim 4 wherein said delaymeans comprises a continuous magnetic medium; a plurality of recordingdevices positioned adjacent said recording medium and selectivelyconnected by said selecting means to said input means; and a pluralityof reading devices positioned adjacent said magnetic arsenite mediumselectively connected by said selecting means to said selectivelyoperated recording devices.

6. Ay recording system in accordance with claim 5 cornprising inaddition a digit analyzer for determining the number of said groups ineach entry; and means controlled by said group determining digitanalyzer for stopping the operation of said selected recording devicesand for normalizing said lirst and said second-mentioned digitanalyzers.

7. A system for sorting a plurality of multidigital entries comprisingselector means for predetermining the sorting digit; a magnetic mediumhaving recorded thereon groups of signals representing said plurality ofmultidigital entries; a reading device for converting said groups ofsignals to time-modulated electrical pulses; a digit counting circuitcontrolled by said reading device; a first magnetic delay circuitconnected to said reading device and controlled by said selector means;ten magnetic recording means selectively connectable to said first delaycircuit; a first digit analyzer controlled by said selector means andsaid counting circuit for connecting in accordance with said sortingdigit one of said ten magnetic recording means to said rst magneticdelay circuit; a second digit analyzer controlled by said countingcircuit upon the occurrence of a predetermined digit which indicates thenumber of digits in the entry; a second magnetic delay' devicecontrolled by said second digit analyzer; and terminating meanscontrolled by said second magnetic delay device for disconnecting theconnected one of said ten magnetic recording means and for normalizingsaid first and said second digit analyzers; said iirst and said seconddigit analyzers each comprising a continuous magnetic medium, arecording device positioned adjacent said magnetic medium and controlledby said counting circuit, a plurality of reading devices positionedadjacent said recording medium and a coincident circuit controlled bysaid reading devices positioned adjacent said recording medium and bysaid reading devices for converting said groups ot signals forselectively connecting said magnetic recording means to said first andsaid second delay devices.

8. A system for sorting a plurality of multidigital entries inaccordance with claim 7 wherein said rst and said second delay deviceseach comprises a continuous magnetic medium; a plurality of recordingdevices positioned adjacent said medium and selectively connectable bysaid selector means to said reading device; a plurality of readingdevices positioned adjacent said magnetic medium selectively connectableby said selector means to the connected one of said ten magneticrecording means, and an erasing device positioned adjacent said magneticmedium, the interval accorded between the energization of the connectedone of said recording devices and the connected one of said readingdevices being greater than tbe time necessary for said groups of signalspreceding tbe group corresponding to said sorting digit plus the timefor readying said connected recording means.

9. in a sorting system, a magnetic input medium having a plurality ofgroups of signals recorded thereon with cach of said groups having aplurality of subgroups; signal responsivev means for converting saidsubgroups of signzds toV subgroups of pulse time coded electricalsignals including means for continuously moving said medium; a digitanalyzer responsive to a predetermined one of said subgroups ofelectrical signals; a plurality of magnetic recorders selectivelycontrolled by said digit analyzer in accordance with said predeterminedsubgroups of electrical signals; and magnetic delay means for storingsaid subgroups of electrical signals until the completion of theoperation of said digit analyzer.

a0 in a sorting system in accordance with claim 9 wherein said delaymeans comprises a continuous magnetic medium; a plurality of recordingdevices positioned adjacent said magnetic medium and selectivelyconnectable in accordance with said predetermined subgoups to saidresponsive means; a plurality of reading devices positioned adjacentsaid magnetic medium and selectively connectable in accordance with saidpredetermined subgroup to the subgroup of the selected one of saidrecorders and an erasing device positioned adjacent said magneticmedium, the interval accorded between the energization of the connectedone of said recording devices and the connected one of said readingdevices being greater than the time necessary for said groups of signalspreceding said predetermined subgroup plus the time for readying saidselected recorder.

li. A system for classifying recorded groups of items of intelligence inaccordance with the character of a predetermined one of said items ineach group comprising seiector means for adjusting the system inaccordance with the position of said predetermined item; counting fordetermining the position of each of said items; an item analyzercontrolled by said counting means and by said selector means fordetermining the characier of said predetermined item; a plurality ofcharacter output devices selectively operated under control of saidanalyzer for recording said groups; and delay means for storing saiditems until the operation of said selected output devices.

12. A system in accordance with claim 1l comprising in additionanalyzing means for determining the number of said items in each of saidgroups; and terminating means controlled by said analyzing means forstopping the operation of said selected output devices after therecording of the last of said items of each of said groups by saidselected output devices.

13. A system in accordance with claim l2 wherein said item analyzercomprises a continuous magnetic mcdium, a recording device positionedadjacent said magnetic medium and controlled by said selector means andsaid counting means, a plurality of reading devices positioned adjacentsaid recording medium, and a coincident circuit controlled by saidreading devices for selectively connecting said output devices to saiddelay means.

Shepherd Feb. 9, 1954 Newby Apr. 13, 1954

